From 4714fd175c657e0104042f82e99ca48e2299bc2f Mon Sep 17 00:00:00 2001
From: cbenthin <carsten.benthin@intel.com>
Date: Mon, 21 Nov 2016 01:12:33 -0800
Subject: [PATCH] compile fix for ancient tbb versions without task_arean
 support

---
 kernels/bvh/bvh_builder_twolevel.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernels/bvh/bvh_builder_twolevel.cpp b/kernels/bvh/bvh_builder_twolevel.cpp
index 579f455149..bdaf1d7665 100644
--- a/kernels/bvh/bvh_builder_twolevel.cpp
+++ b/kernels/bvh/bvh_builder_twolevel.cpp
@@ -137,7 +137,7 @@ namespace embree
         /* compute PrimRefs */
         prims.resize(refs.size());
 
-#if defined(TASKING_TBB) && defined(__AVX512F__)
+#if defined(TASKING_TBB) && defined(__AVX512F__) && USE_TASK_ARENA
         tbb::task_arena limited(32);
         limited.execute([&]
 #endif
@@ -186,7 +186,7 @@ namespace embree
             bvh->set(root,LBBox3fa(pinfo.geomBounds),numPrimitives);
           }
         }
-#if defined(TASKING_TBB) && defined(__AVX512F__)
+#if defined(TASKING_TBB) && defined(__AVX512F__) && USE_TASK_ARENA
           );
 #endif